ohhh baby powder? is it cornstarch based?
Youtube videos don't lie, but how do you know they are correct?
The seals on our rigs are rubber. That means they could be any variety of 2 or 3 actual compounds, all sort-of requiring different things.
Take a look at this: http://303products.com/product-uses/rubber
303 Aerospace Protectant maybe the best engineered material for rubber seals.